I just finished installing a "new" motor in my '91 N/A RX7. I'm pretty much positive that I have everything hooked up right. Anyways, I've got spark at all 4 plugs, & I have fuel. When I try to start it, it starts and runs for about 1/2 a second, a second at most, and then shuts off. I've tried moving the CAS to try and adjust the timing but it doesn't seem to help. I've also tried starting fluid, no luck. At this point I'll try pretty much anything, so if anyone has any ideas, suggestions, or whatever, please let me know. All help is appreciated.

 

hmmm... have you compression tested it? if compression ok, is the stock AWS system intact and working? if not you will have to hold the throttle for 30 seconds or so on startup, then it should idle on its own. Do you have known fuel to the rail or injectors? injectors may be clogged/faulty if fuel is surely making it to the rails. You may want to check the voltage to the fuel pump as well as low voltage can lead to all kinds of strange stuff. I am no expert however so im sure there is more to check.

 

I haven't compression tested it, but the guy I bought it from said the compression was in the 90's (PSI) on both rotors. I'll go take a look at the AWS system. I can definitely smell the gas at the back of the car (2 1/2 in. piping with two APEXi N1's), and like I said, although it runs for less than a second, that's still technically running so I "think" it has fuel. And I'll look at the fuel pump voltage. And when it does start, it wont stay alive no matter how much gas you give it. Grr... Anyone else have some more suggestions to try?

 

could also be a massive vacuum leak. If it starts and you can keep it running by giving it gas but dies when you let off thats a pretty good sign the compression is bad.

 

Anyone else have some ideas?

 

Is it a fresh rebuild or was it removed from another car and new to yours? Could be a vac. leak.

 

New to mine. Bought from "coolcars44". He said he's not sure of the mileage, but that the compression is in the 90's on the faces both rotors. I finished putting it in a day or two ago. Went to start it, and it starts but shuts off after less than a second. Never even reaches idle. Just the initial rev from being started the it dies.

 

My bet is vacuum leak, my car started for about 2 seconds and then quit when I got it. I got it to run at 3000 rpm only by holding the gas on the floor. It has 105 psi front and rear and did the same thing. I found that three vacuum lines were missing (one was attached to the auxilliary ports). When I fixed the vacuum lines (actually just plugged them in) the car ran just fine.

Basically, from what I have found, if the engine will start, no matter how long it runs, and then restart right after, it is not bad compression.

Check your AFM, that your fuel pump continues to run after the car has started, for vacuum leaks and then let us know.

Hope this helps.

 

I'm wondering if i might have found my problem. Anyone know what this wire is for? It's the small wire that's light green with a black stripe on it.


http://tinypic.com/view.php?pic=8elj8rq&s=1
http://tinypic.com/view.php?pic=72bkj88&s=1
http://tinypic.com/view.php?pic=7x1sacj&s=1

 

For One..If you smell gas out the Tail pipe,and have tried starting it Over and Over and OVER.it is Flooded..another thing is do you have the AFM hooked up?..if not,the Car will Start and die,over and over again!..it never really Starts,,just catches and goes BlahhhhhhP!

 

Yeah, the AFM (that is the air flow meter, right?) is hooked up. Just to see if for some weird it would work, we tried unplugging the Mass Airflow Meter, and as expected, no luck. It might also be worth mentioning that I did NOT re-install the air pump or the a/c compressor. Several of my friends came and took a look and they're stumped as well. I wish I knew what that wire went to, because it's may be the problem.